The objective of this work is to study the plastic limit load of cylindrical vessels with different lateral angles $θ$ under increasing internal loadings. Three full size test vessels with different structure dimensions were fabricated for testing. A three-dimensional, nonlinear, finite element numerical simulation was also performed. The approximate plastic limit load was obtained using a twice-elastic-slope criterion. The plastic deformation characteristics for the analysis model are discussed. The results show that distinct deformation characteristics occurred on the three experimental vessels. The intersection area shrank in the longitudinal section of the cylinder, while bulges appeared in the transverse section. The angle between the axis of lateral and the cylinder increased. The plastic limit loads determined by experiment and numerical simulation methods are in good agreement.

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